Today’s Vergecast: How to train your data.

Training data is the raw material of the AI industry. Claude, ChatGPT, Gemini, and the rest are built on top of oceans of stuff. What is that stuff? Books. Blog posts. YouTube videos. News articles. All of it and more, in virtually incomprehensible quantities. Alex Reisner, a staff writer at The Atlantic who has been investigating training data, explains how AI companies get all this data, why they’d really prefer you not know what’s in it, and whether training data could ever be a fair trade. Posts from this author will be added to your daily email digest and your homepage feed. Posts from this topic will be added to your daily email digest and your homepage feed. Posts from this topic will be added to your daily email digest and your homepage feed. Posts from this topic will be added to your daily email digest and your homepage feed. A free daily digest of the news that matters most. The Verge is a part of PMX Global, LLC, a subsidiary of Penske Media Corporation. © 2026 VM Publishing, LLC. All rights reserved. Sign in to see your notifications or create an account to join the conversation.